全球智库信息集成服务系统(G2TT): Electroconvection in a homeotropic bent-rod nematic liquid crystal beyond the dielectric inversion frequency.

G2TT

来源类型	Article
规范类型	其他
DOI	10.1021/jp803798g
	Electroconvection in a homeotropic bent-rod nematic liquid crystal beyond the dielectric inversion frequency.
	Kumar P; Hiremath US; Yelamaggad CV; Rossberg AG; Krishnamurthy KS
发表日期	2008
出处	The Journal of Physical Chemistry B 112 (32): 9753-9760
出版年	2008
语种	英语
摘要	We characterize the structural transitions in an initially homeotropic bent-rod nematic liquid crystal excited by ac fields of frequency/well above the dielectric inversion point fi. From the measured principal dielectric constants and electrical conductivities of the compound, the Can-Helfrich conduction regime is anticipated to extend into the sub-megahertz region. Periodic patterned states occur through secondary bifurcations from the Freedericksz distorted state. An anchoring transition between the bend Freedericksz (BF) and degenerate planar (DP) states is detected. The BF state is metastable well above the Freedericksz threshold and gives way to the DP state, which persists in the field-off condition for several hours. Numerous +1 and -1 umbilics form at the onset of BF distortion, the former being largely of the chiral type. They survive in the DP configuration as linear defects, nonsingular in the core. In the BF regime, not far from fi, periodic Williams-like domains form around the umbilics; they drift along the director easy axis right from their onset. With increasing fi, the wave vector of the periodic domains switches from parallel to normal disposition with respect to the c vector. Well above fi, a broadband instability is found.
主题	Evolution and Ecology (EEP)
URL	http://pure.iiasa.ac.at/id/eprint/8523/
来源智库	International Institute for Applied Systems Analysis (Austria)
引用统计
资源类型	智库出版物
条目标识符	http://119.78.100.153/handle/2XGU8XDN/128805
推荐引用方式 GB/T 7714	Kumar P,Hiremath US,Yelamaggad CV,et al. Electroconvection in a homeotropic bent-rod nematic liquid crystal beyond the dielectric inversion frequency.. 2008.